The dead co-pilot of the crashed Virgin Galactic sub-orbital space craft Michael Alsbury moved a crucial control surface lock to an unlock position seconds before it tumbled and broke apart according to US crash investigators.
The acting chair of the National Transportation Safety Board, Christopher Hart told a third public briefing on the crash investigation that the abnormal action was recorded by a cockpit camera.
Hart said a control lever that governed the actions of the twin ‘feathers’ that are used to stabilize the craft, a two pilot six passenger SpaceShipTwo model, was moved from LOCK to UNLOCK nine seconds after its rocket engine had ignited.
He said the normal procedure was not to move the lever to UNLOCK until the craft has reached mach 1.4, but the space vehicle was moving at about mach 1 or the speed of sound at that time. The reason for keeping the feathers locked down until mach 1.4 was to prevent aerodynamic forces extending them prematurely.
Ground photos showed what appeared to be the feathers being flung away from the main body of the space craft, then obscured by what appears to be a cloud of unburned fuel, however the NTSB has recovered the fuel tanks and engines intact, meaning there was no explosion involving either.
Hart said that the two seconds after the UNLOCK action occurred the long boom like ‘feathers’ moved of their own accord, and not through pilot action, to their vertical deployed position. In normal operation the pilots would have to first select UNLOCK and then move a separate control lever to manually deploy them.
“The feather lever (not the unlock lever) was not moved,” Hart said.
“Until that point telemetry appears normal ….and then ceased.”
The acting NTSB chair said “We are a long way from finding the cause of the accident. What we are saying today is not a statement of cause but a statement of fact.”
He said because it was a test flight a very large and diverse amount of information was received in real time from the flight, as well as recovered from multiple recording devices including cameras.
[There are external cameras on SpaceShipTwo in a position to have documented the changes in control surfaces and the break up of the craft under aerodynamic forces].
Hart said the investigation would be looking at numerous lines of enquiry including pilot training and the issue as to whether there was any pressure on the pilots to fly when they did.
Earlier today the Crikey Insider bulletin published a feature on the pressures that were building on Virgin Galactic well before the ill fated test flight.